Grinding wheel and holder therefor



1,641,791 p 1927- F. J. TONE GRINDING WHEEL AND HOLDER THEREFOR FiledJune 23. 1925 PatentedSept. 6, 1927.

UNITED STATES OFFICE.

FRANK J. TONE, OF NIAGARA FALLS, NEW 'YORK, ASSIGNOR TO THE CARBORUNDUMCOMPANY, OF NIAGARA FALLS, NEW YORK, .A CORPORATION OF PENNSYLVANIA.

GRINDING WHEEL AND HOLDER THEREFOR.

Application filed June 23, 1925. Serial No. 39,108.

For grinding certain classes of work, such as the inside surfaces ofbath tubs to prepare them for enameling, and similar castings, forexample, the grinding wheel is mounted on the end of a flexibleoperating shaft, in order to enable the operator to move the wheel frompoint to point, and both the face and the edge of the grinding wheel areused as grinding surfaces. This work is very hard on the grinding wheeland causes it to wear away rapidly, necessitating frequent replacementof wheels. Heretofore such wheels have been formed cup-shaped and theoperatingsha'ft extended through the bottom of the cup and the wheelsecured thereto by means of a nut engaging the threaded end of the shaftinside the hollow cup. With this method of mounting it was impossible towear down the wheel lower than the nut, so that the stub to be thrownaway constituted a considerable portion of the wheel. Also, there wasconsiderable danger to the operator by reason of the liability of therapidly rotating wheel cracking and then flying to pieces, as thismethod of mounting did not afford any support for the cracked wheeltending to prevent it from flying to pieces.

By the present invention I have rovided an improved form of grinding weel and mounting therefor designed to overcome the above objectionablefeatures inherent in the old method of mounting grinding wheels of thischaracter.

The invention is illustrated in the accompanying drawings, wherein:

Figure 1 is a side elevation of a grindlng wheel and grinding wheelholder mounted on the end of a flexible operating shaft and embodying apreferred form of my invention- Figure 2 is a plan view of the grindingwheel and its holder;

Figure 3 is a section on the line III-III of Figure 2; and

Figure 4 is a sectional view, showing a modified form of holderembodying my invention.

Referring to the construction shown in Figures 1 to 3, inclusive, thegrinding wheel 2 has a central bore 3 and a reduced hub portion 4projecting from one end face thereof and exteriorly screw-threaded.

The holder comprises a plate 5 having a central hole therein to receivethe screwthreaded end 6 of the operating shaft 7, said plate beingadapted to be clamped between an enlarged portion 8 of the shaft and anut 9 mounted on said screw-threaded end 6. The plate 5 has ascrew-threaded periphery adapted to receive a screw-threaded ring 10.The upper portion of this ring is of reduced internal diameter, therebyproviding a shoulder 11 between the two portions of the ring adapted toengage the upper face of the plate 5. The upper portion of the ring isscrew-threaded for engagement with the threads of the hub portion of thewheel. When the ring 10 is screwed on the plate 5 so as to bring theshoulder 11 into engagement with the face of the plate, the parts areheld against relative turning by one or more locking screws 12. Setscrews 13 are mounted in screw-threaded openings in the plate 5. Whenthe grinding wheel 2 has been screwed into the ring 10 so as to bringthe end face of the hub portion 4; into engagement with the face of theplate 5, the set screws 13 are adapted to be tightened up so as tocreate suflicient friction between the threads of the hub portion 4. andthe threads of the ring 10 and between the end face of the hub portion 4and the ends of the set screws to prevent relative turning of the wheeland holders when the wheel is being operated.

In the construction shown in Figure 4:, the plate 5 is provided with anintegral screwthreaded flange 14. instead of with a separate ringmember.

It will be seen that by the present invention I have provided aconstruction wherein the grinding wheel is adapted to be worn downalmost, if not quite, to its hub portion, which constitutes a relativelysmall portion of the wheel. Moreover, the hub portion is surrounded bythe holder so that the holder 1 will tend to hold the wheel together incase it cracks in service, thereby lessening the danger of the wheelexploding. However, I make no claim broadly to these features, as theyconstitute the invention of Hobart 0. Beach, and are claimed in hiscopending application Serial No. 39,011 filed of even composed of bondedabrasive grains having bonded abrasive date herewith. The term rindingwheel as herein used means a w eel formed of bonded abrasive grains.

I claim:

1. In a grinding wheel, a disk composed of ains having a reduced hubportion on one ace, said hub being externally threaded, and a metalholder screwed onto said externally threaded hub rtion.

2. In a grinding wheel assemb y, a disk composed of bonded abrasivegrains having a reduced integral hub portion on "one face thereof, saidhub portion being externally threaded, and a metal holder having: aninternally threaded flangefitting around and screwed onto the reducedhub portion.

3. In a grinding wheel assembly, a disk an integral reduced hub portionon one face thereof, said hub being externally threaded a metal holderhaving an internally threade flange fitting around and screwed onto thereduced. hub portion and having a central disc portion, and a drivinghub connected with the said disc portion. i

4. In a grinding wheel assembly, a grinding disk composed of bondedabrasive grains having an integral hub portion on one face thereof, saidhub portion being externally threaded, a metal holder having a centralportion and an interiorly threaded flange, said flange being screwedonto the said reduced hub portion, and a set screw in the centralportion adapted to press against the end of the reduced hub portion.

- In testimony whereof I have hereunto set my hand. 7 I

FRANK J. TONE.

